The American glass industry produces over 17 million tons of glass products each year. Of that, over 11 million tons are glass containers, bottles and jars. The State of Michigan, as a representative state, generates over 645 thousand tons of glass container waste each year. The state does have a deposit law so it is estimated that approximately one-half of this amount is recovered. Of the remaining half, a few cities, towns and counties have recycling programs but these in total only amount to approximately 1 percent of the glass recovered. It is estimated that there is approximately 60 thousand tons of glass scrap available for recovery. This scrap glass is a valuable resource.
While many people recognize that scrap glass is recoverable, the cost of recovering the glass is, in most cases prohibitive. By the time the glass is cleaned to remove food and labels, sorted by color, crushed and then transported to a glass plant for reuse, the cost of a ton of scrap glass approaches or exceeds the cost of a ton of new glass. In view of the very slim margin for profit, most cities and towns have neglected recovering scrap glass as an economic and environmental project.
In accordance with the teachings of the present invention, construction materials have been developed which use recycled glass which does not require color separation, cleaning, long haul and expensive transportation or rigid sizing specifications.
In building roads and highways and in constructing homes and buildings, an important consideration is the proper drainage of the soil. In building a road, for example, ditches are dug along the edge of the road bed. The ditches are then partially filled with crushed stone followed by a porous plastic pipe covered with a cloth sleeve or sock and then completely filled with sand and gravel. In this construction, the water can percolate down through the sand and gravel into the porous pipe where it can be carried off. Around building foundations, it is also necessary to install similar drain fields to carry water away from the footings so that the building can sit on stable ground, minimizing the possibility of settling and water leaking through the foundation wall. All of these drain construction projects require the use of expensive materials, such as hollow pipe and carefully sized aggregate.
In the construction of highways, it often occurs that the sides of an embankment, for example near a road drainage ditch, have to be supported and protected from sliding down into the ditch. It is particularly important to not only support but to adequately drain the embankment to protect the support material from being washed away. All of these problems are compounded in the northern climates where the drainage system is subject to freezing, expansion and contraction and ground heaving. Also within the cross section of a road or highway, it is common practice to promote drainage in the subgrade zone to minimize frost heave and control the water table rise due to capillary pressures associated with temperature differentials and variable soil compositions, thus extending pavement life.